H34.1 Central retinal artery occlusion

Name of the Condition

• Central Retinal Artery Occlusion

Summary

Central retinal artery occlusion (CRAO) is a blockage of the central retinal artery, which supplies blood to the retina. This blockage disrupts blood flow and can lead to sudden, painless vision loss in the affected eye. The condition is a medical emergency due to the risk of permanent retinal damage and vision impairment.

Causes

CRAO is typically caused by an embolus (e.g., from atherosclerotic plaque or cardiac sources) or thrombus blocking the central retinal artery. Other contributing factors may include vasospasm, inflammatory conditions, or trauma to the artery.

Risk Factors

• Advanced age
• Hypertension
• Atherosclerosis
• Cardiovascular disease
• Diabetes mellitus
• High cholesterol
• Smoking
• Hypercoagulable states
• Carotid artery disease

Symptoms

• Sudden, painless vision loss in one eye
• Reduced visual acuity (e.g., "blacking out" or "fogging" of vision)
• Visual field defects (e.g., altitudinal or sectoral loss)
• Relative afferent pupillary defect (RAPD) in the affected eye

Diagnosis

Diagnosis involves a comprehensive eye examination, including visual acuity testing, dilated funduscopy (to assess retinal whitening, cherry-red spot, or arterial narrowing), and imaging studies such as fluorescein angiography or optical coherence tomography (OCT) to evaluate retinal perfusion and structure. Systemic evaluations (e.g., carotid Doppler, cardiac workup) may be performed to identify underlying causes.

Treatment Options

Treatment aims to restore retinal blood flow and minimize damage. Immediate interventions may include ocular massage, anterior chamber paracentesis, or systemic therapies (e.g., thrombolytics, vasodilators). Long-term management focuses on addressing underlying risk factors (e.g., controlling blood pressure, cholesterol) and preventing recurrence.

Prognosis and Follow-Up

Prognosis depends on the duration of the occlusion and promptness of treatment. Vision may improve with early intervention, but permanent loss is common if the blockage persists. Follow-up includes regular eye examinations to monitor for complications (e.g., neovascularization) and systemic evaluations to address underlying conditions.

Complications

• Permanent vision loss
• Retinal ischemia or infarction
• Neovascularization of the iris or retina (neovascular glaucoma)
• Optic atrophy

Lifestyle & Prevention

• Manage hypertension, diabetes, and cholesterol through diet, exercise, and medication.
• Avoid smoking and limit alcohol consumption.
• Maintain regular cardiovascular check-ups.
• Promptly address symptoms of transient vision loss or systemic vascular issues.

When to Seek Professional Help

Seek immediate medical attention for sudden, painless vision loss in one eye, as CRAO requires urgent evaluation to preserve vision.

Tips for Medical Coders

Code H34.1 is used for central retinal artery occlusion. Documentation should specify the eye affected (e.g., right, left, bilateral) and any associated complications (e.g., neovascular glaucoma). Ensure clinical notes support the diagnosis and exclude transient or branch retinal artery occlusions, which use different codes.